Characterization of Ba_(0.35)Sr_(0.65)TiO3 Made by Sol-Gel Method with X-Ray Powder Diffraction, Field Emission Scanning Electron Microscopy and Impedance Spectroscopy in Capacitor Application

摘要

A thin film of Barium Strontium Titanate(BST)of ferroelectric material of Ba_(0.35)Sr_(0.65)TiO3 has been made using sol-gel method and annealed at 600, 650, and 700°C in order to obtain its crystalline structure.This thin film was characterized using X-Ray Diffraction(XRD), Field Emission Scanning Electron Microscopy(FESEM)and Impedance Spectroscopy.The results of XRD characterization show a graph of intensity against angle 2θ.The XRD patterns of Ba_(0.35)Sr_(0.65)TiO2 have many peaks and confirmed that the material of Ba_(0.35)Sr_(0.65)TiO3 has cubic crystalline structure and their lattice parameter is in average of 2.399A.The results of FESEM characterization show that the thickness of thin films of Ba_(0.35)Sr_(0.65)TiO3 at 600, 650, and 700°C were 21.21 nm, 34.61 nm and 39.08 nm, respectively.The values of capacitance at the frequency of 100 Hz with temperature of 600, 650, and 700°C are 4.84 × 10~(-11)F, 5.24 × 10~(11)F and 5.61 × 10~(11)F, respectively.The dielectric constant of the thin films of BST at the frequency of 100 Hz with temperature of 600, 650, and 700°C are 5.47, 5.90 and 6.28, respectively.While the loss of dielectric values of the thin films of BST at 100 Hz with temperature of 600, 650, and 700°C are 0.03, 0.08 and 0.12, respectively.The result of characterization by Impedance Spectroscopy shows that the higher the frequency, the smaller complex capacitance, dielectric constant and dielectric loss.Generally, the higher annealed temperature, the higher complex capacitance and dielectric constant.